The Chinese seismic bureau said that the quake occurred at 05:28 a.m. local time (21:28 GMT on Wednesday) in waters near Yilan County with the epicenter located at the depth of 30 kilometers (18.6 miles).
The New Taipei City Fire Department said at about 08:00 local time that a 60-year-old woman was found dead after a wardrobe fell on her as the tremor started.
The earthquake has led to serious power outages with about 10,000 families were left without electricity. Meanwhile, according to TaiwanPower company, electricity on the island was restored at 10:00 a.m. local time.
The earthquake has also affected transport connections in Taiwan. Railroad traffic in Yilan Country was temporarily suspended, but restored at 08:30 a.m. local time.